A demonstration and evaluation of trajectory mapping

Author

Morris, Gary Allen

Date

1995

Advisor

Few, Arthur A., Jr.

Degree

Doctor of Philosophy

Abstract

The problem of creating synoptic maps from asynoptically gathered data has prompted the development of a number of schemes. Most notable among these schemes are the Kalman filter, the Salby-Fourier technique, and constituent reconstruction. This thesis presents a new technique, called trajectory mapping. Trajectory mapping employs a simple model of air parcel motion to create synoptic maps from asynoptically gathered data.
To assess the applicability of the technique, four sources of trajectory mapping errors were analyzed. The analysis revealed that (1) the computational error is negligible; (2) measurement uncertainties can result in errors which grow with time scales on the order of a week; (3) isentropic approximations lead to errors characterized by time scales of a week; and (4) wind field inaccuracies can cause significant errors in individual parcel trajectories in a matter of hours. All the studies, however, indicated that while individual trajectory errors can grow rapidly, constituent distributions, such as those depicted in trajectory maps, are much more robust, maintaining a high level of accuracy for periods on the order of several weeks.
The trajectory mapping technique has been successfully applied to a variety of problems. First, trajectory mapping was employed in the study of dynamical wave-breaking events. Second, trajectory mapping was applied in satellite data validation studies, both for the determination of instrument accuracy and precision. Third, trajectory mapping was used to assess the accuracy of the meteorological wind fields. Such demonstrations imply that trajectory mapping will become an important tool in answering questions of global change, particularly the issue of ozone depletion.